Ventilator management in Duchenne muscular dystrophy and postpoliomyelitis syndrome: twelve years' experience

The ventilator management protocol followed over the last 12 years in 23 patients with Duchenne muscular dystrophy (DMD) and six polio survivors with chronic respiratory failure (CRF) secondary to the late effects of poliomyelitis or postpolio syndrome (PPS) is reviewed. After the onset of respiratory failure, patients with DMD continued to show a classic course of progressive, generalized muscle weakness and a steadily declining vital capacity from an average of 482mL to 336mL. The DMD group required an average increase of 0.95 hours in their daily use of assisted ventilation per year. Their overall average length of survival was increased from 19 years 9 months to 25 years 9 months. Members of the postpolio group, to date, have shown no significant decrease in muscle strength nor have they needed more than nocturnal ventilation. Recommended evaluation and pulmonary follow-up for patients with CRF secondary to neuromuscular disease is outlined. Most of these patients can be managed for a number of years with body ventilators before a tracheotomy is necessary.     

神经肌肉病患者功能评定的临床应用进展

大部分神经肌肉病属于罕见病,其中相对较为常见的是Duchenne型肌营养不良和脊髓性肌萎缩症。神经肌肉病的一个重要特征是进行性残疾,因此功能评定对评价神经肌肉病患者的疾病严重程度、运动功能以及活动能力非常重要。目前功能评定包括肌力、关节活动度、姿势、活动能力等方面,涉及多种评定工具,但尚未形成统一标准。精确、合理的评定方法对多学科管理团队为患者制定个体化治疗方案具有重要意义。     

Noninvasive ventilation in neuromuscular disease: equipment and application

Noninvasive support of ventilation is commonly needed in patients with neuromuscular disease. Body ventilators, which are used rarely, function by applying intermittent negative pressure to the thorax or abdomen. More commonly, noninvasive positive-pressure ventilation (NPPV) is used. This therapy can be applied with a variety of interfaces, ventilators, and ventilator settings. The patient interface has a major impact on comfort during NPPV. The most commonly used interfaces are nasal masks and oronasal masks. Other interfaces include nasal pillows, total face masks, helmets, and mouthpieces. Theoretically, any ventilator can be attached to a mask rather than an artificial airway. Portable pressure ventilators (bi-level positive airway pressure) are available specifically to provide NPPV and are commonly used to provide this therapy. Selection of NPPV settings in patients with neuromuscular disease is often done empirically and is symptom-based. Selection of settings can also be based on the results of physiologic studies or sleep studies. The use of NPPV in this patient population is likely to expand, particularly with increasing evidence that it is life-prolonging in patients with diseases such as amyotrophic lateral sclerosis. Appropriate selection of equipment and settings for NPPV is paramount to the success of this therapy.     

Maladies musculaires en réanimation. Quand les évoquer ? Comment orienter la recherche diagnostique ?

Muscular and neuromuscular junction diseases include several hundreds entities. Some are acquired like inflammatory myopathy, drug-induced myopathy, and myasthenia gravis; others are inborn like muscular dystrophy, congenital myopathy, metabolic myopathy, and channelopathy. Even if scarce, they can be encountered in the intensive care unit (ICU), mainly in three situations: (1) severe worsening or complication of a known muscular disease; (2) suspicion of muscular disease in a patient presenting with acute motor weakness, severe bulbar dysfunction, rhabdomyolysis, acute respiratory distress or cardiac dysfunction (altered systolic function, impaired heart conduction or arrhythmia); (3) occurrence of muscle disease acquired while the patient is hospitalized in the ICU, that can be responsible for prolonged mechanical ventilation and increased mortality. Some muscular diseases should be suspected when patients present with encephalopathy, epilepsy, metabolic or ionic disturbance (acidosis, hypo- or hyperkaliemia) even in the absence of muscular symptoms. We will successively discuss which circumstances may suggest an underlying muscular or neuromuscular junction disease, how diagnosis can be assessed, and finally which are the main muscular or neuromuscular diseases according to their clinical presentation in the ICU.     

An evaluation of home volume ventilators that support open-circuit mouthpiece ventilation

BACKGROUND: Open-circuit mouthpiece ventilation (MPV) is a form of noninvasive ventilation that can be used to provide portable daytime ventilatory support for neuromuscular patients with chronic respiratory failure. MPV has been reported to reduce the risk of respiratory infection due to tracheostomy, and to improve cough and voice function and patient quality of life. Despite these potential benefits, mouthpiece ventilation is not widely used. This may be due in part to the fact that little information is available as to which ventilators can support this application. OBJECTIVE: To determine which volume-cycled portable home ventilators currently available in the United States will support MPV, and what peak inspiratory flow rates create adequate circuit pressure to prevent low-pressure alarming. METHODS: We used a commercially available MPV breathing circuit with a set tidal volume range of 500\N1,000 mL with each of 8 ventilators currently available in the United States. RESULTS: Six of the 8 ventilators supported MPV: Respironics Lifecare PLV-100 and PLV Continuum, Mallinckrodt Achieva PSO2, Pulmonetics LTV800, Newport HT50, and Uni-Vent Eagle 754.     

Alternatives to endotracheal intubation for patients with neuromuscular diseases

OBJECTIVE: To evaluate the usefulness of continuous noninvasive mechanical ventilation and mechanical coughing aids to avoid endotracheal intubation and tracheostomy during episodes of acute respiratory failure in patients with neuromuscular disease. DESIGN: We conducted a prospective cohort study at the respiratory medicine ward of a university hospital to study the success rate of the use of continuous noninvasive mechanical ventilation and manually and mechanically (CoughAssist) assisted coughing to avert endotracheal intubation in 24 consecutive episodes of acute respiratory failure for 17 patients with neuromuscular disease. The noninvasive mechanical ventilation and coughing aids were used to reverse decreases in oxyhemoglobin saturation and relieve respiratory distress that occurred despite oxygen therapy and appropriate medication. Noninvasive mechanical ventilation was delivered by volume ventilators (Breas PV 501) alternating nasal/oronasal and oral interfaces. RESULTS: Noninvasive management was successful in averting death and endotracheal intubation in 79.2% of the acute episodes. There were no significant differences in respiratory function between the successfully treated and unsuccessfully treated groups before the current episode. Bulbar dysfunction was the independent risk factor for failure of noninvasive treatment (P < 0.05; odds ratio, 35.99%; 95% confidence interval, 1.71-757.68). CONCLUSIONS: Intubation can be avoided for some patients with neuromuscular disease in acute respiratory failure by some combination of noninvasive mechanical ventilation and mechanically assisted coughing. Severe bulbar involvement can limit the effectiveness of noninvasive management.     

Duchenne muscular dystrophy: prolongation of life by noninvasive ventilation and mechanically assisted coughing

OBJECTIVE: To quantitate prolongation of survival for patients with Duchenne muscular dystrophy with the use of noninvasive intermittent positive-pressure ventilation (IPPV) with and without access to a protocol involving mechanically assisted coughing. DESIGN: In this retrospective review of all patients with Duchenne muscular dystrophy visiting a neuromuscular disease clinic, patients were trained to use mouth piece and nasal IPPV and mechanically assisted coughing to maintain oxyhemoglobin saturation >94% (protocol). Survival was considered prolonged when noninvasive IPPV was required full time. RESULTS: Ninety-one of 125 patients used noninvasive IPPV part time for 1.9 +/- 1.3 yr, and 51 went on to require it full time for 6.3 +/- 4.6 yr. Of the 31 noninvasive IPPV users who died without access to the protocol, 20 died from respiratory causes and seven died from cardiac causes. None of the 34 full-time noninvasive IPPV users with access to the protocol underwent tracheotomy or died from respiratory complications during a period of 5.4 +/- 4.0 yr, whereas three died from heart failure. Five patients with no breathing tolerance were extubated or decannulated to continuous noninvasive IPPV. CONCLUSIONS: Noninvasive respiratory aids can prolong survival and permit extubation or decannulation of patients with Duchenne muscular dystrophy with no breathing tolerance.     

The growing role of noninvasive ventilation in patients requiring prolonged mechanical ventilation

For many patients with chronic respiratory failure requiring ventilator support, noninvasive ventilation (NIV) is preferable to invasive support by tracheostomy. Currently available evidence does not support the use of nocturnal NIV in unselected patients with stable COPD. Several European studies have reported benefit for high intensity NIV, in which setting of inspiratory pressure and respiratory rate are selected to achieve normocapnia. There have also been studies reporting benefit for the use of NIV as an adjunct to exercise training. NIV may be useful as an adjunct to airway clearance techniques in patients with cystic fibrosis. Accumulating evidence supports the use of NIV in patients with obesity hypoventilation syndrome. There is considerable observational evidence supporting the use of NIV in patients with chronic respiratory failure related to neuromuscular disease, and one randomized controlled trial reported that the use of NIV was life-prolonging in patients with amyotrophic lateral sclerosis. A variety of interfaces can be used to provide NIV in patients with stable chronic respiratory failure. The mouthpiece is an interface that is unique in this patient population, and has been used with success in patients with neuromuscular disease. Bi-level pressure ventilators are commonly used for NIV, although there are now a new generation of intermediate ventilators that are portable, have a long battery life, and can be used for NIV and invasive applications. Pressure support ventilation, pressure controlled ventilation, and volume controlled ventilation have been used successfully for chronic applications of NIV. New modes have recently become available, but their benefits await evidence to support their widespread use. The success of NIV in a given patient population depends on selection of an appropriate patient, selection of an appropriate interface, selection of an appropriate ventilator and ventilator settings, the skills of the clinician, the motivation of the patient, and the support of the family.     

Dysfonction hémodynamique au cours du sepsis : approche expérimentale

Long-term noninvasive ventilation (NIV) is increasingly used in children. It requires the delivery of a ventilatory assistance by an interface that connects the patient??s airways, such as a nasal or facial mask, or rarely a nasal canula. NIV is indicated in diseases causing chronic alveolar hypoventilation, including neuromuscular disorders, maxillo-facial or upper airway abnormalities, thoracic deformities, some lung diseases, and disorders of respiratory control. In these diseases, NIV is the first-line treatment when chronic respiratory failure occurs because it is noninvasive and can be applied on demand, preferentially during sleep. The increasing use of NIV in children is explained by the improvement of the diagnosis of chronic alveolar hypoventilation, the availability of pediatric interfaces, and the increasing performance of home ventilators.     

Strategies for providing mechanical ventilation in a mass casualty incident: distribution versus stockpiling

Federal funding provides state public and private health care systems the ability to build and maintain a reserve supply of ventilators for emergency response to mass casualty incidents. Studying and planning the ventilator reserve capability requires subject-matter expertise, identification of best mechanical-ventilation practices and quality care standards, and contingency planning. Natural disasters such as pandemic influenza, or man-made disasters such as bioterrorism could necessitate field use of numerous mechanical ventilators. This paper discusses the pros and cons of stockpiling ventilators at one site (to be distributed as needed to disaster areas) versus increasing the number of ventilators at all hospitals. Respiratory-device corporations, respiratory professional associations, and respiratory therapists should be involved in the planning and development of respiratory mass casualty response systems.     

Noninvasive ventilation in the intensive care unit -- is it still negligible?

Non-invasive positive pressure ventilation (NIPPV) has been discussed comprehensively in the last years, but usage of non-invasive ventilation in Intensive Care Units is rare. The reasons may be uncertainty in indications and difficulties in handling the masks and ventilators. In the last years the introduction of full face masks and respiratory helmets has made it possible to ventilate patients with unusual facial forms and to avoid problems of pressure necrosis. Software components designed for NIPPV are available for standard respirators. Indications for NIPPV (neuromuscular diseases, spinal abnormalities, chest wall malformations, COPD, cardiogenic pulmonary edema) have been ensured in clinical trials. No sufficient data are available for the application of NIPPV in weaning and respiratory failure following extubation. Indication for NIPPV becomes apparent when therapy starts in early stage with sufficient ventilation pressure. Compared to standard therapy, no reliable advantage has been seen for NIPPV in hypoxic hypercapnia respiratory failure except for malignant diseases. However, prophylactic use in patients with high risk might be conceivable. For these patients strict criteria of termination are required to avoid missing the time point for intubation. Gas exchange disturbances in advanced lung fibrosis, pneumonia and ARDS are not amenable to NIPPV. Contraindications for NIPPV are non-compliant patients, absence of cough- and pharyngeal reflexes as well as retention of secretions and malignant ventricular arrhythmia. Relative contraindications are catecholamine-dependent circulatory collapse and acute myocardial infarction, since sufficient data for NIPPV are missing.     

Contractures in neuromuscular disease.

The percentage of subjects with contractures, mean maximal loss of range, and relative contracture indices are reported in 230 patients, with 11 diseases seen in a neuromuscular disease clinic during a five-year period. The highest percentage of contractures occurred in patients with Duchenne muscular dystrophy. The number of contractures was significantly greater (p less than .001) (1) in the lower than in the upper extremities; (2) in diseases considered myopathic than in those considered neuropathic; (3) in diseases that are X-linked than in those that are not; and (4) in rapidly progressive than in slowly progressive diseases.     

Long-term management of ventilated-assisted individuals: the Boston University experience.

In the 4 1/2 years beginning in January 1981, the University Hospital at the Boston University Medical Center admitted 46 ventilator-assisted individuals to its Respiratory Care Center and discharged 38 of them to their homes with ventilators. Of the 46 admitted, 23 had COPD and 23 had neuromuscular or skeletal disorders. All the latter were successfully sent home, and 15 of the 23 with COPD went home. At follow-up in 1985, of the 38 patients managed at home for periods of 1 to 51 months, 30 were surviving and 4 with COPD and 4 with neuromuscular disorders had died. One died immediately after discharge, one who had amyotrophic lateral sclerosis lived 9 months at home before dying, and the other 6 lived at home a year or more before dying. These results were made possible by an inpatient facility that had the goal of improving the quality of life of ventilator-assisted persons. This was done by the use of portable ventilators on motorized wheelchairs, by the use of traditional rehabilitation techniques, and by encouraging and training patients to become independent and responsible for their own personal and respiratory care. The hospital-based Respiratory Care Center is staffed by a team from physical therapy, occupational therapy, respiratory therapy, rehabilitation nursing, social service, psychiatry, rehabilitation medicine, and otolaryngology. A pulmonary physician directs the program and a respiratory nurse specialist is co-director and oversees its daily operation. The rehabilitation process has six stages: Stage 1 is stabilization, Stage II is evaluation, Stage III is rehabilitation planning, Stage IV is rehabilitation training, Stage V is discharge planning.(ABSTRACT TRUNCATED AT 250 WORDS)     

Secondary cardiomyopathy accompanied by neuromuscular disorders

There are many neuromuscular diseases associated with cardiomyopathy. Cardiac involvement with progressive muscular dystrophy (Duchenne and Becker type) and some type of limb-girdle muscular dystrophy were characterized by impaired left ventricular systolic function, such as dilated cardiomyopathy like status. In Friedreich ataxia various types of left ventricular hypertrophy were reported. While in myotonic dystrophy and Emery-Dreifuss muscular dystrophy, conduction disturbance and tachyarrhythmia are common types of cardiac manifestation. The severity of cardiac involvement in these diseases is not necessarily concordant with that of skeletal muscle. Recently the genes of these diseases were identified by linkage analysis. We review cardiac abnormalities of these diseases, especially relationship between severity of cardiac disorder and gene abnormalities.     

Augmentative and alternative communication for people with progressive neuromuscular disease

Individuals with progressive neuromuscular disease often experience complex communication needs and consequently find that interaction using their natural speech may not sufficiently meet their daily needs. Increasingly, assistive technology advances provide accommodations for and/or access to communication. Assistive technology related to communication is referred to as augmentative and alternative communication (AAC). The nature of communication challenges in progressive neuromuscular diseases can be as varied as the AAC options currently available. AAC systems continue to be designed and implemented to provide targeted assistance based on an individual's changing needs.     

Prevalence of chronic obstructive pulmonary diseases in general clinics in terms of FEV1/FVC

Background: The prevalence of chronic obstructive pulmonary disease (COPD) continues to increase all over the world. Nonetheless, COPD is often misdiagnosed in general clinics because of insufficient use of spirometry. Objectives: To estimate the prevalence of COPD in general clinics in Japan, we performed spirometry to screen patients who consulted general clinics. Methods: Patients 40 years of age and older who consulted clinics in Nagasaki Prefecture, Japan, for non‐respiratory diseases and who met certain inclusion criteria had their airflow limitation measured by spirometry. We defined COPD as forced expiratory volume in the first second (FEV₁) over forced vital capacity (FVC) (FEV₁/FVC) of < 70% in patients without active pulmonary disease, including physician‐diagnosed asthma. Results: Of the 1424 patients included in the study, 193 (13.6%) showed airflow limitation. Airflow limitation was significantly related to older age, male gender and cumulative pack‐years. FEV₁/FVC in patients with hypertension and chronic hepatitis were significantly lower than in patients without these diseases when adjusted for age, gender and pack‐years. Conclusions: We showed that there are potentially a number of cases with COPD that are undiagnosed by general physicians in Japan. Measuring airflow limitation by spirometry in smokers with coexisting diseases, such as hypertension and chronic hepatitis, may be very beneficial because COPD is thought to be a systemic disease. The distribution of spirometers to general clinics is definitely needed to detect undiagnosed COPD.     

Effect of Lung Volume Recruitment on Pulmonary Function in Progressive Childhood-Onset Neuromuscular Disease: A Systematic Review

ObjectivesThe focus of this systematic review was to consider whether lung volume recruitment (LVR) has an effect on pulmonary function test parameters in individuals with progressive childhood-onset neuromuscular diseases. The review was registered on PROSPERO (No. CRD42019119541).Data SourcesA systematic search of the CINAHL, MEDLINE, AMED, EMCARE, Scopus, and Open Grey databases was undertaken in January 2019 considering LVR in the respiratory management of childhood-onset neuromuscular diseases.Study SelectionStudies were included if either manual resuscitator bags or volume-controlled ventilators were used to perform LVR with participants older than 6 years of age. Critical appraisal tools from the Joanna Briggs Institute were used to assess the quality of studies. Nine studies were identified, 6 of which were of sufficient quality to be included in the review.Data ExtractionData extraction used a tool adapted from the Cochrane effective practice and organization of care group.Data SynthesisResults were compiled using a narrative synthesis approach focused on peak cough flow, forced vital capacity, and maximum inspiratory capacity outcomes.ConclusionsLimited evidence suggests an immediate positive effect of LVR on peak cough flow and a potential long-term effect on the rate of forced vital capacity decline. Considering the accepted correlation between forced vital capacity and morbidity, this review suggests that LVR be considered for individuals with childhood-onset neuromuscular diseases once forced vital capacity starts to deteriorate. This review is limited by small sample sizes and the overall paucity of evidence considering LVR in this population group. Controlled trials with larger sample sizes are urgently needed.     

Neuromuscular disorders associated with failure to wean from the ventilator

Objective To determine, by retrospective chart analysis, the frequency, type and significance of neuromuscular disorders in patients whose clinical features suggested a neuromuscular cause of failure to wean.Background Failure to wean is a common and difficult problem in critical care units. While a neuromuscular cause may be suspected in some patients, the frequency and type has not been determined utilizing comprehensive electrophysiological studies of limbs and the respiratory system. Such knowledge may aid in patient management and prognosis.Methods The clinical setting was a critical care/trauma centre that admits 1500 patients per year, approximately 500 being on ventilators for longer than five days. We analyzed the hospital charts of 40 patients admitted to the unit during three years, whose respiratory assessment suggested a neuromuscular cause for failure to wean from the ventilator. To investigate this possibility, we performed electrophysiological studies of the limbs and also of the respiratory system by phrenic nerve conduction and needle electromyography of the chest wall and diaphragm. The results were compared to 25 healthy controls.Results 38 of 40 patients (95%) had a neuromuscular disorder: 25 — critical illness polyneuropathy, 2 — Guillain-Barré syndrome, 4 — diabetic and critical illness polyneuropathy, 2 — uremic and critical illness polyneuropathy, 10 — an abnormality of central drive, 5 — unilateral phrenic nerve palsy, 3 — a neuromuscular transmission defect, and 5 — a primary myopathy. Fifteen (38%) had a combination of disorders. Patients with more severe polyneuropathy took longer to wean, a mean of 136 versus 52 days (p=0.007).The severity of the polyneuropathy had no effect on mortality.Conclusions Electrophysiological studies of limbs and the respiratory system are together valuable in confirming the presence, and identifying the specific type of neuromuscular cause for difficulty in weaning from the ventilator. This information is important in patient management and prognosis.     

Symptoms, clinical and physiological findings motivating home mechanical ventilation in patients with neuromuscular diseases.

OBJECTIVE: To clarify the relationship between symptoms, clinical signs and physiological abnormalities that were motivating the initiation of home mechanical ventilation in patients suffering from neuromuscular diseases. METHODS: From The Swedish Home Mechanical Ventilation Register we identified 352 patients with neuromuscular diseases and we looked at circumstances (acute vs elective) and clinical motives for starting ventilatory support. RESULTS: Home mechanical ventilation was commenced electively in 268 patients (76%) and among these daytime sleepiness was the most common motive, being reported in 56% of the patients. In the 24 children with spinal muscular atrophy, however, 96% started ventilation electively and cough insufficiency was the most common motive. The patients were moderately hypercapnic (PaCO(2): 7.0 kPa, SD 1.3). None of the clinical motives were related to the PaCO(2) level. Average PaO(2) was above 8 kPa in all groups, but lowest in the patients with post-polio and dystrophia myotonica. Mean vital capacity was close to 40% of predicted, but significantly lower in the Duchenne patients (26% of predicted). CONCLUSION: Daytime sleepiness was the most common clinical symptom motivating home mechanical ventilation in this group of patients with chronic hypercapnic respiratory insufficiency secondary to neuro/myopathies. Respiratory function testing is therefore suggested to be included in the diagnostic work up of daytime sleepiness in these patients.